Networks are presently being deployed that exploit the advantages of asynchronous transfer mode (ATM) communications. Communication with asynchronous transfer mode involves transmitting voice and data information in packets called ATM cells. ATM uses an optimization technique known as statistical multiplexing to increase the information carrying capacity of a given communications line compared to traditional schemes such as time division multiplexing (TDM).
Because of the enhanced information carrying capacity available with ATM, there has been some use of ATM communications networks to link large offices within an organization. With this type of arrangement, all of the voice and data traffic at a source office that is intended for a destination office can be converted to ATM format using an ATM multiplexer. The ATM traffic from the source office is demultiplexed at the destination office. If the communications traffic between the source and destination offices is sufficient, using this type of ATM arrangement may be cost effective.
However, there has been no known way in which to use this type of ATM arrangement to interconnect equipment with the other networks in the existing network infrastructure (i.e., traditional networks such as the long haul voice network). As a result, the customer must typically arrange for network service at the source and destination offices in addition to ATM service. Providing such additional communications services can be costly, because access charges (i.e., the charges associated with providing transport from a customer premises to a carrier point-of presence) are a significant component of the total cost of providing a service.
It is therefore an object of the present invention to provide a communications system in which the advantages of ATM communications are used to improve the way in which a customer is provided with access to networks in the existing network infrastructure.